But entomologists occasionally stumble on male Timema insects ... This “cryptic sex” introduces genetic diversity into stick insect populations and might aid their long-term survival.

Stick insect sex “can go on for several months,” he said. It’s not clear whether this is welcome to the female. The male stick insect plants himself on the female’s back and attaches ...

The researchers focused on the rare males of Ramulus mikado, a stick insect species in Japan, where parthenogenesis is predominant. Their analysis of male reproductive behavior reveals new findings.

Once you find that special someone, it’s hard to let go. The same is true for animals that literally attach themselves to their mates—some just briefly, and some for hours, or even for life.

Many stick insects display extreme sexual dimorphism, with females unrecognizable from their male companions. In 2018, Paul Brock, a scientific associate at the Natural History Museum in London ...